Thursday, November 1, 2018

Congenital Amusia: Understanding of the Musical Mind and Brain

Lee, Harin. 2018. “Congenital Amusia: Understanding of the Musical Mind and Brain.” PsyArXiv. November 1. doi:10.31234/osf.io/xbwfq

Abstract: The current paper aims to provide a comprehensive review of some of the recent researches on congenital amusia, demonstrating how the behavioural, brain-imaging, and genetic studies have extended our understanding of the musical mind and brain. Moreover, it discusses the gaps in the literature that needs to be addressed in future research.

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Peretz and her colleagues (2007) investigated 9 large families of amusic probands with 71 members with matched control of 10 families with 75 members. The study showed that the disorder is a defect in pitch discrimination but not timing in music, and it is heritable. While the prevalence of the disorder was only 3% among first-degree relatives of control families, 39% was present in the amusic families. In a twin study of 136 monozygotic and 148 dizygotic twin pairs, participants were asked to discriminate the wrong note in a well-known song melody, and genetic model-fitting showed that shared genes were greater determinant than shared environment with estimate of 70 to 80% heritability (Drayna, Manichaikul, de Lange, Snieder, & Spector, 2001). Likewise, some studies argue that individuals’ musicality in general are more dependent to genetic basis compared to number of practice hours in the context of musical achievement (Peretz, 2016). Even the motivation to commit more hours of practice seems to be genetically influenced. The topic of whether musicality is innate or shaped through the environment is an on-going debate.

Nevertheless, recent studies have also demonstrated that amusia can be improved through laboratory training and raises a more interesting question (Liu, Jiang, Francart, Chan, & Wong, 2017; Whiteford & Oxenham, 2017, 2018). In a study conducted by Whiteford and Oxenham (2017), 20 amusics and matched pair of controls undertook four sessions to train in pitch-discrimination task. After the training, 11 of the amusics no longer met the criteria of MBEA and one year follow up test showed that the improvement is maintained (Whiteford & Oxenham, 2018). This is controversial to the previous findings that amusia is a life-long deficit and questions the current diagnosis of MBEA and whether the disorder is influenced by genetics.